Concept explainers
Interpretation:
The difference in the stabilities ofcycloheptatrienone andcyclopentadienone needs to be explained and the structure of Diels–Alder adduct of cyclopentadienoneneeds to be drawn.
Concept introduction:
In accordance with theHuckel’s rule,
Anaromatic compound contains conjugated pi bonds.
Antiaromatic compounds contain
Diels-Alder reaction is an addition reaction of a conjugated diene and an
The general reaction of Diels–Alder is as follows:
Diels Alder reaction is between a conjugate diene and a reactant containing double bond (dienophile) to form the product and the product is called adduct.
Diels Alder reactions are highly stereospecific. The configuration, if dienophile is retained in the product and the reaction, is syn addition.
The dienes react with dienophiles in cis forms rather than trans forms.
Endo and exo refer to the orientation of dienophile and its electron withdrawing group, when it reacts with a diene in Diels–Alder reaction.
The reaction with orientation of electron-withdrawing group of dienophiles under the
The reaction with orientation of electron-withdrawing group of dienophiles away from the
Endo is favored in the transition state of Diels–Alder reaction because of its lower energy.
If a compound is stable, it has lower energy and if a compound is unstable, it has higher energy.
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EBK ORGANIC CHEMISTRY
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- Organic ChemistryChemistryISBN:9781305580350Author:William H. Brown, Brent L. Iverson, Eric Anslyn, Christopher S. FootePublisher:Cengage Learning